#include<stdio.h>
main()
{int x;
 printf ("Input number:");
 scanf("%d",&x);
 printf("number of decimal form:%d\n",x);
 printf("it's binary form:");
 printb(x, sizeof(int)*8);
 putchar('\n');
}

printb (x, n)
    int x,n;
    {if(n>0){
        putchar('0' + ( (unsigned)(x&(1<<(n-1)) )>>(n-1)));
        printb(x,n-1);
    }



    }

//吴昌源



